tbuckley/cabot-search huggingface dataset:
Abstract A046: Heterogenous nuclear ribonucleoprotein E1 regulates leukemia inhibitory factor receptor (LIFR) expression through FAM3C in mammary epithelial cells
Authors: William S. Streitfeld, Annamarie C. Dalton, Philip H. Howe
Journal: Cancer Research (2023)

Abstract Leukemia inhibitory factor receptor (LIFR) signals through signal transducer and activator of transcription 3 (STAT3), a transcription factor that is associated with poor prognosis due to its overexpression and/or hyperactivity in 40% of breast cancer cases. LIFR has been defined as either a promoter or suppressor of metastasis in mammary carcinoma, and recently we have shown that its expression is significantly upregulated following loss of the RNA-binding protein heterogenous nuclear ribonucleoprotein E1 (hnRNP E1, “E1”). We have further shown that E1 is a regulator of the epithelial-to-mesenchymal transition (EMT) and of differentiation in mammary epithelium. Mechanistically, E1 acts as a tumor suppressor by binding to and inhibiting translation of mRNAs involved in EMT and cellular self-renewal, including the cytokine FAM3C. We have demonstrated that FAM3C binds to LIFR in the extracellular space and activates STAT3. Herein, we characterize induction of LIFR expression in response to FAM3C/LIFR signaling, and show that E1 upregulates LIFR transcription through FAM3C, involving initiation at the LIFR promoter locus. Induction of LIFR expression in mammary epithelial cells has been shown to be associated with tumor initiation, breast cancer stem cells, and metastasis. Additionally, our bioinformatic analysis reveals a signature of transcriptional regulation associated with FAM3C/LIFR interaction. Comparison between RNA-sequencing data from our mouse model of mammary carcinoma and human mammary carcinoma cell lines reveals common biological pathways and potential therapeutic targets. Future directions will be aimed at investigating the effect of modulation of LIFR expression during tumor dissemination in vivo. Citation Format: William S. Streitfeld, Annamarie C. Dalton, Philip H. Howe. Heterogenous nuclear ribonucleoprotein E1 regulates leukemia inhibitory factor receptor (LIFR) expression through FAM3C in mammary epithelial cells [abstract]. In: Proceedings of the AACR Special Conference: Cancer Metastasis; 2022 Nov 14-17; Portland, OR. Philadelphia (PA): AACR; Cancer Res 2022;83(2 Suppl_2):Abstract nr A046.
Abstract IA007: Regulation of metastasis efficiency via mitochondrial genetics
Authors: Danny R. Welch
Journal: Cancer Research (2023)

Abstract While there has been increasing appreciation for the roles of mitochondria in cancer, most efforts investigating the genetics of cellular functions study only the nuclear genome. To overcome technical complications of studying the specific contributions of mitochondrial genetics, we created mitochondrial nuclear exchange (MNX) mice by transferring an oocyte nucleus from strain-x into an enucleated oocyte from strain-y. Using MNX mice, we made the following discoveries demonstrating the profound role(s) of mtDNA on several complex phenotypes. - Crossing nuclear genome-matched female mice with male transgenic mice bearing oncogenes, tumorigenicity and metastasis were up- or down-regulated depending upon mtDNA. - MNX mice exhibit different autochthonous tumor formation. - When syngeneic (i.e., histocompatible) mammary and melanoma cells were injected into MNX mice, metastasis changed 3-5X, depending on mtDNA SNP. C57BL/6J mtDNA inhibited metastasis while C3H/HeN mtDNA increased metastasis. - MNX mice have selectively altered epigenetic marks (DNA methylation and histone marks) in the nuclear genome. - MNX mice with higher ROS form more metastases. Scavenging ROS reduced metastasis. - Baseline immune profiles differ in MNX mice compared to nDNA-matched counterparts and polarization states of myeloid populations infiltrating lung metastases were also significantly different. - Metabolomic profiling of &amp;gt;5000 metabolites showed minor differences, none of which appear to correlate with the above-referenced phenotypic changes. - MNX mice have distinct gut microbiota than matched wild-type strains, suggesting mitochondrial-bacterial communication. Together, these results demonstrate that mitochondrial genes are among metastatic quantitative trait loci by intrinsic and extrinsic mechanisms. Candidate signals from mitochondria to the nucleus or bacteria will be reported. And since mitochondrial SNP are markers of genetic ancestry, our findings also suggest that mtDNA SNP could serve as prognostic biomarkers and partially explain racial disparities in disease severity. Support: Susan G. Komen for the Cure (SAC11037), METAvivor Research &amp; Support Inc., National Foundation for Cancer Research, National Cancer Institute P30-CA168524. Citation Format: Danny R. Welch. Regulation of metastasis efficiency via mitochondrial genetics [abstract]. In: Proceedings of the AACR Special Conference: Cancer Metastasis; 2022 Nov 14-17; Portland, OR. Philadelphia (PA): AACR; Cancer Res 2022;83(2 Suppl_2):Abstract nr IA007.
Abstract A014: Transcriptional regulation of basal leader cell identity during collective breast cancer invasion
Authors: Andrea E. Doak, Rose Qu, Kevin J. Cheung
Journal: Cancer Research (2023)

Abstract An early step in breast cancer progression is invasion of tumor cells into surrounding tissues. In many breast cancers, particularly ductal carcinomas, this invasion is accomplished by tumor cells migrating as a cohesive group. This often involves cells that take on heterogeneous roles as either leader or follower cells. Studies in common mouse and human breast cancer models have established that leader cells express high levels of keratin-14 (K14) and other basal epithelial markers. The presence of these K14+ cells promote metastasis and predict poor prognosis. The molecular mechanisms regulating K14+ leader cell identity and the methods for targeted depletion of these cells remain obscure. Here we performed time-sampled single cell RNA-sequencing in 3D type I collagen-embedded tumor organoids isolated from the MMTV-PyMT luminal B model of breast cancer. 11 distinct cellular transcriptional states were identified, and through correlation with K14 expression and invasive strand formation we classified one of the states as leader cells. Having confirmed the leader cell cluster markers spatially localize to the invasive front, we next asked which transcription factors were enriched, reasoning that transcription factors could be master regulators of leader cell fate. Three different shRNAs targeting ten genes were systematically evaluated for their effects on collective invasion and keratin-14 transcription. Each transcription factor was designated as either an invasion promoter or invasion suppressor depending on the correlation between transcription factor expression and organoid invasion. Studies are ongoing investigating the impact of invasion-promoting and invasion-suppressing transcription factors on cellular transcriptional states and metastatic dissemination in-vivo. We propose that targeting invasion-suppressing pathways could be combined with therapies that specifically target and eliminate K14+ invasive cells. To this end, we have identified multiple candidate druggable targets and specific surface markers expressed in K14+ invasive cells. Citation Format: Andrea E. Doak, Rose Qu, Kevin J. Cheung. Transcriptional regulation of basal leader cell identity during collective breast cancer invasion [abstract]. In: Proceedings of the AACR Special Conference: Cancer Metastasis; 2022 Nov 14-17; Portland, OR. Philadelphia (PA): AACR; Cancer Res 2022;83(2 Suppl_2):Abstract nr A014.
Abstract PR017: Differences in melanoma lipid metabolism among distinct metastatic sites
Authors: Thomas P. Mathews, Sarah Muh, Arin B. Aurora, Sean J. Morrison
Journal: Cancer Research (2023)

Abstract Metastasis is a very inefficient process in which few disseminated cancer cells survive. We developed a patient-derived xenograft assay in which melanomas engraft and spontaneously metastasize (Quintana Nature 456:593-598). Using this assay, we discovered that melanoma cells experience a spike in reactive oxygen species during metastasis and that distant metastasis is limited by oxidative stress (Piskounova Nature 527:186-191). Successfully metastasizing cells undergo reversible metabolic changes during metastasis that increase oxidative stress resistance. For example, melanoma cells in lymph experience less oxidative stress and form more metastases than melanoma cells in the blood (Ubellacker Nature 585:113-120). This is true in both patient-derived melanomas growing in immunocompromised mice and mouse melanomas growing in syngeneic immunocompetent mice. Cells metastasizing through blood, but not lymph, appear to undergo ferroptosis, a form of cell death marked by lipid oxidation. Multiple differences between lymph fluid and blood plasma may contribute to this difference in oxidative stress, including higher levels of oleic acid in lymph. Oleic acid is a monounsaturated fatty acid that protects melanoma cells from ferroptosis, apparently by reducing the abundance of oxidizable polyunsaturated fatty acids (PUFAs) in phospholipids. In the current study we found that some PUFAs sensitize melanoma cells to lipid peroxidation and cell death more than others. Moreover, we analyzed the lipid profiles of common sites of distant metastasis – liver, brain, kidney, pancreas, bone marrow, lung, and liver – and found that the PUFA compositions of these tissues varies significantly. This raises the possibility that metastasizing melanoma cells may incorporate more PUFAs into their phospholipid membranes and exhibit increased ferroptosis sensitivity in some metastatic sites as compared to others. We found that melanoma cells isolated from metastatic sites by flow cytometry had higher levels of PUFAs in their phospholipid membranes compared to those isolated from subcutaneous tissues. These cells isolated from distal sites also exhibited higher levels of lipid ROS and contained higher levels of oxidized lipid species compared to subcutaneous tumors. These data suggest that the lipid metabolism of metastatic tumors reflects both lipid availability in the metastatic site as well as cell-intrinsic differences in lipid metabolism, both of which contribute to lipid ROS. Both cell-intrinsic and cell-extrinsic lipid metabolism likely influence the ability of melanoma cells to survive in distinct metastatic sites during metastasis. Citation Format: Thomas P. Mathews, Sarah Muh, Arin B. Aurora, Sean J. Morrison. Differences in melanoma lipid metabolism among distinct metastatic sites [abstract]. In: Proceedings of the AACR Special Conference: Cancer Metastasis; 2022 Nov 14-17; Portland, OR. Philadelphia (PA): AACR; Cancer Res 2022;83(2 Suppl_2):Abstract nr PR017.
Abstract A036: Juxtacrine signaling between macrophage and cancer cell inhibits radiation-induced ferroptosis in syngeneic colon cancer
Authors: Sang Wha Kim, Hyewon Chung, Seung Hyeok Seok
Journal: Cancer Research (2023)

Abstract Although radiotherapy (RT) is one of the most common modalities for cancer treatment, radioresistance remains an intractable challenge. RT induces intratumoral infiltration of macrophages for the clearance of injury debris, but rather tumor-associated macrophages confer fitness advantages to cancer cells after RT. Here, we report that tumor-associated macrophage instigates radioresistance by inhibiting RT-induced cell death in a contact-dependent manner. Mechanistically, RT increases receptor tyrosine kinases (RTKs) expression in cancer cells to enable direct interaction with macrophages, resulting in reduced cancer cell ferroptosis triggered by RT. Unbiased RNA-seq analysis of RTK-dependent juxtacrine signaling in macrophages further reveals a profound remodeling of the irradiated tumor microenvironment (TME) via regulation of macrophage polarization and cytotoxic T cell-mediated antitumor responses. Using a syngeneic colon cancer model, we found that ablation of RTK-induced juxtacrine signaling sensitized tumor to RT through increasing cancer cell ferroptosis and impairing macrophages-mediated TME. Collectively, our study supports the RTKs as a new radiosensitizing target via attenuation of the interaction between cancer cells and macrophages during RT. Citation Format: Sang Wha Kim, Hyewon Chung, Seung Hyeok Seok. Juxtacrine signaling between macrophage and cancer cell inhibits radiation-induced ferroptosis in syngeneic colon cancer [abstract]. In: Proceedings of the AACR Special Conference: Cancer Metastasis; 2022 Nov 14-17; Portland, OR. Philadelphia (PA): AACR; Cancer Res 2022;83(2 Suppl_2):Abstract nr A036.
Abstract B024: TBX2highmiR-375-3plowRBPJhigh signaling drives prostate cancer bone metastatic phenotype via exosomes
Authors: Girijesh Kumar Patel, Sayanika Dutta, Hamed Khedmatgozar, Manisha Tripathi, Srinivas Nandana
Journal: Cancer Research (2023)

Abstract Recent studies have shown that exosome secretion by prostate cancer (PCa) cells fosters multiple facets of PCa progression and metastasis, mediated in particular through exosomal micro RNAs (miRs) that dictate gene expression changes. However, the molecular mechanisms through which exosomal miRs orchestrate bone remodeling that facilitates the establishment of a pre-metastatic niche (PMN) at the distant metastatic site i.e. bone remain elusive. We have identified that TBX2, a transcription factor that we previously reported plays a key role in PCa metastasis, represses miR-375-3p thereby resulting in de-repression/upregulation of its target RBPJ, an effector of Notch signaling and an established driver of PCa metastasis. Further, the unbiased identification of miR-375-3p as the topmost miR repressed by TBX2, in combination with experiments that genetically manipulate miR-375-3p in the context of TBX2 modulation, point to a crucial biological function of miR-375-3p as a key mediator in RBPJ regulation exerted by TBX2. In addition, the study highlights a dual level of RBPJ regulation by TBX2/miR-375-3p signaling i.e. via: a) gene expression changes at the intra-cellular or autocrine level, and b) gene expression changes at the distant site of bone metastasis through inter-cellular/endocrine communication via exosomes. Further, the study implicates TBX2high primary PCa cells in directing bone remodeling activity at the distant metastatic site in a paracrine mode via exosomes in addition to our previously reported role of TBX2 in mediating bone remodeling in an autocrine mode that occurs following metastatic dissemination. Taken together, our study unravels the role of TBX2/miR-375-3p/RBPJ signaling in PCa bone metastatic progression. Citation Format: Girijesh Kumar Patel, Sayanika Dutta, Hamed Khedmatgozar, Manisha Tripathi, Srinivas Nandana. TBX2highmiR-375-3plowRBPJhigh signaling drives prostate cancer bone metastatic phenotype via exosomes [abstract]. In: Proceedings of the AACR Special Conference: Cancer Metastasis; 2022 Nov 14-17; Portland, OR. Philadelphia (PA): AACR; Cancer Res 2022;83(2 Suppl_2):Abstract nr B024.
Abstract B016: Pleiotrophin drives a pro-metastatic immune niche within the breast tumor microenvironment
Authors: Debolina Ganguly, Marcel Schmidt, Morgan Coleman, Tuong-Vi Ngo, Noah Sorrelle, Adrian Dominguez, Jason Toombs, Cheryl Lewis, Yisheng Fang, Fatima Mora, David Ortega, Anton Wellstein, Rolf Brekken
Journal: Cancer Research (2023)

Abstract Metastatic cancer cells adapt to thrive in secondary organs. To investigate metastatic adaptation, we performed transcriptomic analysis of metastatic and non-metastatic murine breast cancer cells. We found that pleiotrophin (PTN), a neurotrophic cytokine, is a metastasis-associated factor that is expressed highly by aggressive breast cancers. Moreover, elevated PTN in plasma correlated significantly with metastasis and reduced survival of breast cancer patients. Mechanistically, we find that PTN activates NF-kB in cancer cells leading to altered cytokine production, subsequent neutrophil recruitment and an immune suppressive microenvironment. Consequently, inhibition of PTN, pharmacologically or genetically, reduces the accumulation of tumor associated neutrophils and reverts local immune suppression resulting in increased T cell activation and attenuated metastasis. Furthermore, inhibition of PTN significantly enhanced the efficacy of immune checkpoint blockade + chemotherapy in reducing metastatic burden in mice. These findings establish PTN as a previously unrecognized driver of a pro-metastatic immune niche and thus represents a promising therapeutic target for the treatment of metastatic breast cancer. Citation Format: Debolina Ganguly, Marcel Schmidt, Morgan Coleman, Tuong-Vi Ngo, Noah Sorrelle, Adrian Dominguez, Jason Toombs, Cheryl Lewis, Yisheng Fang, Fatima Mora, David Ortega, Anton Wellstein, Rolf Brekken. Pleiotrophin drives a pro-metastatic immune niche within the breast tumor microenvironment [abstract]. In: Proceedings of the AACR Special Conference: Cancer Metastasis; 2022 Nov 14-17; Portland, OR. Philadelphia (PA): AACR; Cancer Res 2022;83(2 Suppl_2):Abstract nr B016.
Abstract A004: The role of calcium in metastatic progression
Authors: Kenise Morris, Anne-Laure Papa
Journal: Cancer Research (2023)

Abstract Calcium is essential to the structural stability of integrin proteins implicated in platelet–cancer cell interactions, namely integrins GPIIb/IIIa and avb3, which share a common beta subunit (Pelletier et al., J Biol Chem, 1996), (Zhang and Chen, Cell Adh Migr, 2012). Additionally, calcium is essential for ligand binding to these integrins (e.g., fibrinogen) that bridge platelets and cancer cells (Raborn et al., Biochemistry, 2011) and for the downstream signaling following mechanical and chemical stimulation in the integrin microenvironment (Michelson, Platelets, 2013). Platelet-cancer cell interactions are key players in cancer progression as platelets support metastatic dissemination (Morris et al., Biochim. Biophys. Acta BBA - Rev. Cancer, 2022). Despite previous studies recognizing calcium’s role in integrin stability and function, calcium’s importance for platelet support in cancer progression is not well understood. Therefore, we aim to (1) characterize the receptor expression and ligand binding ability of GPIIb/IIIa and avb3 on respective cells via anti-CD41a (for platelets and breast cancer MDA-MB-231 cells) and anti-avb3 antibody (for lung cancer A549 cells), (2) characterize platelet function by assessing platelet aggregation using light transmission aggregometry and platelet adhesion on a thrombogenic surface, (3) characterize platelet-cancer cell interaction via flow cytometry, and (4) assess cancer cell invasion in the presence of platelets via transwell assay; all in the presence of an environment with calcium chelation and hypercalcemic conditions. Our results demonstrate that platelet GPIIb/IIIa, cancer cell GPIIb/IIIa (MDA-MB-231) and cancer cell integrin avb3 (A549) are modulated with calcium chelation. Additionally, platelet function, specifically aggregation is significantly decreased with calcium chelation and significantly increased with hypercalcemia. We also observed that the interaction between platelets and cancer cells is reduced with calcium chelation, platelet-MDA-MB-231 interaction specifically being significantly reduced in the presence of sodium citrate. Our overall hypothesis is that the observed effect of calcium levels of platelet and cancer cell integrins could have a significant influence on platelet-cancer cell interactions and cancer cell migration in hypercalcemia, often seen in patients with malignancy. A greater understanding of these interactions could have impact for the design of specific inhibitors with anti-metastatic effects and potentially lead to novel targeted therapies to combat metastatic dissemination. Citation Format: Kenise Morris, Anne-Laure Papa. The role of calcium in metastatic progression [abstract]. In: Proceedings of the AACR Special Conference: Cancer Metastasis; 2022 Nov 14-17; Portland, OR. Philadelphia (PA): AACR; Cancer Res 2022;83(2 Suppl_2):Abstract nr A004.
Abstract B040: Leader cells mediate tumor engraftment and promote immunosuppression to drive ovarian cancer progression <i>in vivo</i>
Authors: Amy L. Wilson, Brittany R. Doran, Bashirah Basri, Laura R. Moffitt, Magdalena Plebanski, Andrew N. Stephens, Maree Bilandzic
Journal: Cancer Research (2023)

Abstract Epithelial ovarian cancer (EOC) is most frequently diagnosed at an advanced stage, and is characterized by its high recurrence rate and almost-universal acquisition of chemoresistance. Metastasis of EOC is driven by heterogenous spheroids that passively disseminate throughout the peritoneal cavity, promoting tumor spread and recurrence. We previously identified a sub-population of highly motile and invasive “Leader cells” (LCs) that express the basal epithelial protein KRT14 as an absolute determinant of invasive potential. We demonstrated KRT14 knockout in EOC cells does not impact viability or proliferation, however completely ablates their ability to invade through Matrigel in 2D and 3D format in vitro. Although a role for LCs in mesothelial clearance and invasion has been established, these mechanisms remain poorly understood. Here we show a critical role for KRT14+ LCs in immunosuppression and tumor-immune privilege in vivo. In the ID8 syngeneic EOC mouse model, tumor-specific LC (KRT14) loss (LCKO) impaired ovarian intrabursal primary tumor engraftment and subsequent metastatic spread. Immune phenotyping by flow cytometry revealed that mice bearing LCKO tumors displayed decreased proportions of immunosuppressive tumor-adjacent Tregs and M2 macrophages, and improved CD8+ T-cell/Treg ratios. Conversely, forced LC-overexpression (LCOE) in EOC tumors accelerated metastasis, and promoted tumor-immune evasion via upregulated secretion of suppressive chemokines including CCL22 and CCL5. In addition to their critical role in migration and invasion, the current study provides in vivo evidence that leader cells are mediators of immune suppression in ovarian cancer. This work supports the basis that defining novel strategies to target LCs to promote anti-tumor immunity and limit metastatic progression may be a useful strategy for improved epithelial ovarian cancer therapy. Citation Format: Amy L. Wilson, Brittany R. Doran, Bashirah Basri, Laura R. Moffitt, Magdalena Plebanski, Andrew N. Stephens, Maree Bilandzic. Leader cells mediate tumor engraftment and promote immunosuppression to drive ovarian cancer progression in vivo [abstract]. In: Proceedings of the AACR Special Conference: Cancer Metastasis; 2022 Nov 14-17; Portland, OR. Philadelphia (PA): AACR; Cancer Res 2022;83(2 Suppl_2):Abstract nr B040.